With no crew, no one would be able to fix critical systems if they broke and important work related to the station would come grinding to a halt.

The failure of a Russian Soyuz-FG rocket, which had been carrying fresh astronauts to the International Space Station, or ISS, has raised concerns that the orbital facility might have to go unmanned for a period. This increases the risks to the station, which may suffer damage or another crisis that personnel cannot manage from the ground, and will likely delay planned upgrades and work on associated commercial space projects, as well.

The incident occurred on Oct. 11, 2018, during an otherwise routine launch from the Russian-operated Baikonur Cosmodrome in Kazakhstan. Russia’s space agency Roscosmos says it doesn’t know the exact reason for the failure, the first ever for the improved Soyuz-FG since its first flight in 2001, but that the rocket’s second stage broke up after the first stage separated and dropped away. Russian cosmonaut Aleksey Ovchinin and American astronaut Nick Hague survived thanks to built-in automated failsafes that sent their Soyuz-MS capsule flying from the doomed booster and sailing safely down to earth.

“A deviation from the standard trajectory occurred and apparently the lower part of the second stage disintegrated. The rocket stopped its normal flight and after that the automatic system did its work,” Sergei Krikalyov, Roscosmos’ Executive Director for Manned Flights, said on Oct. 12, 2018. “This could have been caused by the failure of the system of the normal separation, which should have been activated. We will analyze the causes in detail.”

This is not to say that Ovchinin and Hague were never in danger. Their capsule entered especially steep, “ballistic descent,” which involves higher speeds and strain on the spacecraft and its occupants than in a normal re-entry.

Russian Ministry of Defense via AP

The remains of the Ovchinin and Hague's Soyuz-MS capsule after the failed launch on Oct. 11, 2018.

In this situation, “you end up coming in steeper, you get more forces on your body, but it’s survivable,” former Canadian astronaut Chris Hadfield, who was at one time the commander on the ISS, told CBC News. “It’s not what you’d want to do, but it’s [Soyuz] a good, tough reliable system.”

You can watch the full interview below, in which Hadfield explains in more detail what the experience might have been like for Ovchinin and Hague and offers additional insight into the potential impacts of the failed launch.

But while Ovchinin and Hague are thankfully safe, their failure to reach the ISS could still have serious ramifications. Russia Krikalyov said he expected the results of the probe into the accident would be available by Oct. 20, 2018, but there’s no guarantee that the investigation will immediately clear the way for further launches using the Soyuz-FG. All future launches are suspended indefinitely at present.

In the meantime, the principal operators of the ISS, Russia’s Roscomos and America’s NASA, have to decide what the crew on board the station now should do. Those individuals can remain in orbit, but not indefinitely. The Soyuz-MS capsule that brought them there has a very well defined time frame that it can survive in space and still be safe to use. As such, the existing personnel at the orbital facility will have to come back down to Earth in December 2018 or January 2019, or risk getting stranded.

Alexey Filippov/Sputnik via AP

The Soyuz-FG rocket carrying Ovchinin and Hague blasts off from Baikonur on Oct. 11, 2018. It would fail within minutes.

“The Soyuz does indeed have a lifetime,” Kenny Todd, NASA’s mission operations integration manager for the ISS, said in a press conference on Oct. 12, 2018. “There’s a little bit of margin on the other side of that, but not a whole lot of margin. …probably early January we would start to call it sort of the end of life in that particular Soyuz.”

“Theoretically, the ISS can be left without a crew. An unmanned mode is stipulated,” Roscosmos’ Krikalyov explained on Oct. 12, 2018. “We will do everything possible to prevent this because the station was created for manned flights. The procedure to deactivate the station is prescribed but it is undesirable and we will try to avoid it.”

NASA

A Soyuz-MS spacecraft docked with the ISS in 2016.

The procedure the Russian official is talking about involves shutting down or reducing the operation of life support, environmental and other systems on the station. Personnel on the ground would monitor the station remotely and issue commands as necessary to move it out of the way of space debris and other hazards.

This could potentially result in the loss of research, since the experiments may be perishable or otherwise time-sensitive. There would also be no one on board in case something catastrophic does happen, which could put the station as a whole at risk.

Just in August 2018, there was a pressure leak that would not necessarily have been apparent immediately to controllers on the ground, who would have had no way of identifying the exact location and source of the issue or repairing it anyway. The investigation into that mishap is still ongoing.

There’s also the matter of work at and on the station coming to a halt. In addition to the scientific research that goes on there, there had also been plans for a series of spacewalks in October and November 2018 to upgrade the station’s power system and conduct an inspection regarding the pressure leak. Nick Hague was set to be one of those spacewalkers and his absence could limit the ability of the existing crew to perform those tasks.

NASA

NASA astronaut Robert L. Curbeam, Jr., at left, and European Space Agency (ESA) astronaut Christer Fuglesang, conduct a spacewalk during the construction of additional segments of the ISS in 2006.

An unmanned scenario would also almost certainly prohibit test flights of Boeing’s CST-100 Starliner and SpaceX’s Crew Dragon. These two spacecraft are part of NASA's Commercial Crew Program, which is seeking an American substitute for the Soyuz system for the first time since the end of the Space Shuttle program in 2011.

Delays in the development of these capsules could pose its own problems since the U.S. government’s contract with Russia to help get its astronauts to the ISS comes up in April 2019 and severely strained relationsbetween the two countries make it unclear if they will continue to cooperate in this fashion. Renewing the deal with the Kremlin may be unavoidable if the United States wants to continue regular missions to the ISS.

Boeing and SpaceX have suffered delays in the development of their respective crafts, which have pushed back plans for inaugural flights to the station until the first half of 2019. NASA is worried that schedule might still be optimistic.

Boeing

An artist's conception of Boeing's CST-100 Starliner spacecraft.

“We have not seen the [Commercial Crew] program make decisions detrimental to safety,” Patricia Sanders, chair of NASA’s Aerospace Safety Advisory Panel (ASAP), since in her opening remarks at a meeting on Oct. 11, 2018, that came just hours after the rocket failure in Kazakhstan. “But current projected schedules for uncrewed and crewed test flights for both providers have considerable risk and do not appear achievable.”

All of this comes as the ISS enters its twilight period and its future is beginning to become uncertain. Launched in 1998, it was only supposed to remain in orbit until 2020. In 2015, NASA extended Boeing's contract to for various services related to the station and included a requirement to upgrade structural components so that they would last until 2028.

SpaceX

A rendering of SpaceX's Crew Dragon.

At that point, the station may have taken on a very different character. Russia only plans to stay involved with the ISS through 2024 and had previously declared it would not contribute to U.S. plans to extend the station’s lifespan.

This latter decision was in retaliation for American economic sanctions and other responses to the Kremlin’s illegal annexation of Ukraine’s Crimea region and subsequent intervention to support an armed separatist movement in the eastern part of that country in 2014. Since then, though, the ISS has remained one of the few remaining examples of close and public cooperation between the United States and Russia.

Russia does have plans for its own new space station, tentatively known as the Orbital Piloted Assembly and Experiment Complex, or by its Russian acronym OPSEK. The Russians have also looked into detaching their portions of the ISS and flying them off to join that facility, but said it had no plans to actually do so as of 2017.

Penyulap/Craigboy/Leebrandoncremer via Wikimedia

An annotated graphic showing the Russian portions of the ISS, which the Kremlin has suggested in the past that it could split off to form the core of a new space station.

For its part, the United States only has plans to fund its portion of the station into 2025, too. After that it could potentially rent it to private interests. Firms interested in ISS for various purposes, including research and space tourism, could always seek to further extend the life of the orbital facility.

For now, though the most pressing concern remains how to get Ovchinin and Hague to the ISS as soon as is possible and get the crew that’s there now home safely, and do so without leaving the station in a risky unmanned configuration for any period of time.